The disclosures herein relate generally to heat sinks in a computer chassis and more particularly to a clip for retaining heat sink mounting fasteners used for mounting a heat sink in the chassis.
The many electrical components in a computer chassis create a lot of heat which must be removed to keep the system functioning. Many heat removal schemes are used in this environment including fans, heat sinks and combinations thereof. Heat sinks, due to their mass, must be properly supported within the chassis so as to withstand shock and vibration loads.
Heat sinks are often mounted in an abutting relationship with a thermal plate which conducts heat from a heat producing component to the heat sink. Due to the crowded confines of the computer chassis and the crowding and stacking of components therein, sufficient support is sometimes difficult to achieve. This problem is compounded by the desirability for non-threaded connectors and supports which provide for the quick attachment and release of components for the purposes of manufacturing and maintenance. Threaded connectors, such as screws, bolts, etc., have been generally undesirable due to the extended time required to attach and remove them and also due the lack of room available for the manipulation of tools needed to attach and remove such connectors.
In one example of a non-threaded connector, U.S. Pat. No. 4,710,852 discloses a spring steel bayonet type retainer for securing encapsulated semiconductor devices to circuit boards either directly or through an intermediate heat dissipator. This device includes spring fingers and bayonet arms. The retainer is installed by urging the bayonet arms through a hole in a mounting tab of the semiconductor device through the circuit board where barbs on the terminal ends of the bayonet arms lock the arms into the hole. The length of the arms is such that the body portion of the retainer is flexed to compliantly exert a force on the semiconductor device to hold it to the circuit board. This device, however, is not easily removed and is not captive to the device it secures.
In U.S. Pat. No. 5,331,507, a resilient heat sink clip has a pair of legs joined together at one end by an arcuate member. The other ends of the legs each terminate at a hook. The arcuate member bears against a heat sink while pressing it into thermal contact with an electronic device to conduct heat into the heat sink and then into the surrounding atmosphere.
In U.S. Pat. No. 5,625,227, a circuit board has an opening through which a heat sink structure passes. The heat sink is thermally coupled on one side of a die cavity lid. The other side of the heat sink structure engages a metal chassis section which engages the outer plastic wall of a computer.
In U.S. Pat. No. 5,424,913, an access door includes a heat sink having a heat receiving portion positioned to mechanically contact a surface of the component to allow transmission of heat from the component to the heat receiving portion. The heat sink further includes a heat dissipating portion forming an outer surface of the access door that is capable of dissipating heat received from the component via the heat receiving portion into an environment surrounding the computer system. The door cools the component when in the closed position and allows access to the component when in the open position.
Therefore, what is needed is a method and apparatus whereby a fastener used to mount a heat sink in a computer chassis is captive to the heat sink so as to be manually accessible and ready for installing the heat sink in the chassis.